Hydraulic lift actuating mechanism



July 29, 1941- F. KOENIGKRAMER ET Al. 2,250,803

HYDRAULIC LIFT ACTUATING MECHANISM `Filed Aug. '7, 1939 'er/erc/r/(oemlgffmmer lNvENToRs.

ma/)Ma t E y Patented `Fuly 29, 1941 UNITED STATES PATENT ori-nce HYDRAULIC LIFT ACTUATING MECHANISM VFrank Koenigkramer and Frederick Koenigkramer, Cincinnati, Ohio Application August 7, 1939, SerialNo. 288,730 s claims. (ci. 155-26) The present invention relates to an hydraulic lift actuating mechanism of the kind generally associated with barbers and beauticians chairs, physicians chairs and treatment tables, hospital litters and similar equipment havingr a seat or `table portion to be tilted and locked in various inclined positions.

An object of the invention is to provide a lift for devices of the character referred to, with actuating and control means of an improved construction such as will facilitate the operation of the locking means for the seat and table elements of such equipment.

Another object of the invention is to simplify and reduce the number of levers and adjustment devices in equipment of the character mentioned, thereby to reduce manufacturing and maintenance costs while at the same time enhancing the safety and dependability of such equipment.

Another object of the invention is to unify to an'extent heretofore unknown, the various adjustments and movements in control equipment for devices of the kind mentioned, thereby to accomplish the foregoing objects.

These and other objects are attained by the means described herein and disclosed in the accompanying drawing, in which:

Fig. 1 is an elevational view of an hydraulic lift for chairs, tables and the like, including the improved actuating and control mechanism of the invention.

Fig. 2 is a fragmental plan view looking down on the device of Fig. 1.

Fig. 3 is afragmental elevational view of the operating handle details, showing the relationshipV of the parts when operative to release a tilt bar.

l Fig. 4 is a plan View of ayoke which forms a detail of the invention, same being illustrated on a greatly reduced scale.

Fig. 5 is a side View of one form of liftequipped chair having a tilting seat, to which the device of the present invention is applicable.

By way of introduction, reference may be had to the general view of Fig. 5 whereinv'l indicates a frame tiltable about a pivot 8 supported by theV head box or casing 9 of a hydraulic lift mechanism. The lift mechanism ordinarily will consist of a pair of telescopic members I and l2 having a mounting frame i|3 secured to a suitable base I4. Although the frame 1 kin this view is shown as a chair frame, it might alternatively be the frame of a table as suggested hereinbefore. Devices of the general character disclosed in Fig. 5 are lwell known, and as will be readily underallv stood, the frame 'l may be lifted and lowered by manipulating anv operating'lever I9 through an arc inthe upright plane which is substantially parallel to the longitudinal axis of the frame.

In accordance with the present invention, the operating lever has also a movement in a plane transversely of the frame axis, for the purpose or" clamping and releasing a tilt rod or bar li which has a iorward end iii pivoted to a link Il, which link in turn is pivoted at I3 to the frame. When the frame is tilted about the pivotal point 8, the tilt'rod or bar` I5 will be shifted forwardly, that is to the right, upon proper release thereoi' by the operating lever in a manner to be hereafter explained. By clamping the tilt rod `in various Vshifted positions, the inclination of the frame l will be denitely established, until such time as the tilt rod is released for return to they normally inoperative position of Fig. 5. In Figs. 1 and 2,'the tilt rod or bar is indicated at I5. l

Referring to Figs. 1 and 2, it will be observed that the head box or casing 9 is furnished with a bearing 2B, which if desired, may. extend a substantial distance from the wall 2l of the box or casing, and said bearing is adapted to rotatably receive therein an actuating shaft 22 which 'is rotatable, butnot reciprocable, Within the bearing. One of the functions of rotationv of said shaft is' that of operating a plunger rod 23 which serves to elevate and lower the lift post I0. It is immaterial to the present invention whether the hydraulic lift mechanism be of one form or another, however, by Way of explanation it may be assumed that the shaft 22 carries a crank 2li and a crank pin 25 connected with the plunger rod in such manner that rocking of the shaft 22 will properly actuate the hydraulic lift.

The hydraulic lift may be of any acceptabletype,.for example, as disclosed in the Kochs etr al. Patent No. i,1,88`7,647, dated November 15,

As was previously stated, the operating lever I9 kmay be used not only for the purpose of rock-l Y ing the shaft 22, but also for clamping and releasing the longitudinal shiftable tiltrod or bar I5. Toso clamp and release the tilt rod the operating lever I9 is so constructed as to be shiftable'about a pivot 26, in a direction lengthwise of the axisof shaft 22. Thearrangement is such that such movement of the lever about pivot 2t will be effective for clamping and releasing the tilt rod, regardless of the inclination of said lever as determined by the operating' In other words, the operating leverY I9 as disclosed in Fig. 5 may be in the substantially vertical position there illustrated, or it may be in positions to the right or left of the indicated position, without in any way affecting the capability of the lever to clamp or release the tilt rod without rotation of the shaft 22.

The means whereby the foregoing functions are accomplished will now be described in detail. The head box or casing 9 will be seen to include the opposed walls 21 vand 28 through which extends the tilt rod or bar I5. Suitable apertures or bearings 29 may be formed in said opposed walls to permit free longitudinal reciprocation of the rod I5. the rod I5, a pivot rod or shaft 30 maybe provided, the ends 3| and 32 of which provide studs for the pivotal mounting of the spaced arms 33-V Closely adjacent, and parallel tofcomprisea sleeve 49 which is shiftable with the element 4I along the shaft 22, said sleeve having its end 56 in abutment upon the element 4I. Either integrally with or separate from the sleeve is an abutment plate 5I which, if desired, may be in the form of a disc. The plate 5I is adapted to be moved to the left, together with sleeve 49 and cone 4I, by the movement of lever I9 in a clockwise direction about its pivot 26, as indicated in the Fig. 3 illustration'. It will be noted that the pivot 26 for lever I9 is supported in a block 52 which is xed securely to shaft 22 at its outer end, so that rotation of the lever to the Fig. 3

and 34 of a clamping yoke indicated generally by the character 35 (see Fig. 4) The yoke is adapted to be moved about its pivots 3| and 32 only slightly, but it will be seen that the journals 3'6 and 31 thereof through which the tilt bar or rod passes, will bear tightly against the vrod or bar with a shearing force when the yoke is rotated about its pivotal mountings'.

As is most clearly shown in Fig. 1, the free vend of the yoke carries a cam follower 38, which may be in the form of a roller rotatably supported upon a shaft 39 passing through perforate ears 4I) of the yoke. A cam 'which may be in the form of a'cone 4I, is adapted' to be moved longitudinally'of the'shaft 22 for striking the follower 38 and forcing it downwardly for the purpose of moving the yoke about its pivotal mountings 3| and 32. Upon backing the'cam or cone 4| from 43. A set screw orl other suitable adjusting means 46 may apply the necessary force to the adjustable spring seat 44, by threading the screw through the web at the location 41.

From the foregoing, it should be readily apparent that movement of the cam or cone 4| to the left of Fig; 1 will result in lowering the free end of the yoke, thereby tovcompress the springs 42 as the yoke moves about its pivots 3| and'32, but incidental to suchY movement of the yoke, the tilt rod or bar I5 will be loosed in the journals 36 and 31 for shifting movement through the head box 9. Upon retraction of the cam or cone 4|, that is, upon movement thereof to the right in Fig. 1, the follower 38Y will be relieved of the force applied thereto by the cam or cone, whereupon the springs 42 will return the yoke to the elevated position at which the clamping action thereof upon the tilt rod or bar will be reestablished.

By referring to Figs. 1 and 2, it will be seen that a suitable compression spring 48 encircling the shaft 22 with its ends abutting the bearing and the cam or cone 4I, serves always to move the cam or cone to the right, at which position of the latter, the springs v42 exert the necessaryl force for effecting the clamping action between the yoke arms and the tiltrod I5.

The means for shifting the cam or cone 4| longitudinally of shaft 22`includes the same lever I9 that is employed in operating mechanism for elevating and lowering the lift. VSaid means may vposition will place the cam` face 53 of the lever in forceful contact upon the abutment plate 5I, andk by reason of the fact that the shaft 22 is not shiftable lengthwise, due to the integral shoulder 1I] abutting the casing wall 2 I, the abutment" plate necessarily will shift to the left for forcing the cam or cone 4I against the follower 38v of the yoke, thereby to lower the free end of said yoke as heretofore explained, to release the clamping force upon the tilt rod or bar I`5. If desired, the block 52 may carry an extending pin or guide member 54 arranged in substantial parallelism with shaft`22`, which pin or guide member may project through a perforation or slot 55 formed in the abutment plate 5I thereby providing for rotational movement Vof the abutment plate with' the shaft 22 when lever I9 is manipulated for rocking thev shaft and operating the lift mechanism.

Because of 'the probability that the lever I9' will in some instances' assume a position quite close to the seat or table`V frame 1, it is desirable thatmeans be provided for precluding rotation of the operating lever I9 labout its pivot 26 in the counterclockwise direction, since such movement ofthe lever would probably result in interferenceV by the framel 1. Accordingly, a stop 56' is bolted or otherwise fixed to the lever at a proper elevation such that the lower face 51 thereof will bear upon the periphery of abutment plate 5| upon'attempted' rotation of the lever to the left, from the position illustrated by Fig. 1. It will be observed by referring to Fig. 1, that the pivoted end ofthe lever preferably is bifurcated so as to furnish the spaced parallel arms 58 and 59` which embrace the pivot block 52. The fixation of block 5-2 to the end of shaft 22 rmay be eifected' inl any proper manner, such as by means of a' drive fit, a suitable key, or a spline connection, all of which is immaterial to the invention.

In conclusion it may be mentioned that spring 48 is merely auxiliary to springs 4-2-42, and may be omitted if springs 42Q42v be made sufIicientl-y' forceful toshift the camY or cone 4I to the neutral or normal position of Fig. 1. The inclination1 of the face ofcam ory cone 4I may be increased, if necessary, to enable omission of spring 48- as suggested. In constructions' wherein it mayl be consideredv necessary or desirableto have the tilt rod I5 at a higher elevation than the yoke arm, the clampingaction may be effected at a notch or depressionfll formed in each yoke arm.y

The construction ldescribedy and disclosed herein is found to furnish a very convenient and simpley means, all-incorporated in a single operating lever control, for adjusting the height and also thedegree of tilt of a frame suchas-1, or of any other type of framerequiring the vrmovements specified. The constructionavoids then'eed for-a multiplicity of levers or controls, thereby adding to the convenience and the undr'standabilityof operation, 'as we lll as to'fthe appearance ofthe equipment? Additional advantages are stated in the objects at the head of this description, and various minor advantages will be readily apparent to those skilled in the art.

It is to be understood that various modications and changes maybe made in the structural details of the device, within the scope of the appended claims, without departing from the spirit of the invention.V

What is claimed is: Y

1. In a device of the class described, the combinationA of a lift to -be selectively elevated and lowered, and a weight-supporting frame tiltably supported upon the lift, said lift including a head having opposed walls and a shaft bearing extending parallel to said walls, an operating shaft for the lift supported in said bearing rotatably and including means preventing longitudinal sluiting of said shaft, a lever supported upon said shaft for rocking same, transverse pivot means connecting the shaft and lever for movement of the lever arcuately in a plane which passes through the shaft axis, a clamping yoke having arms Ypivoted upon the opposed walls of the lift head, and means for moving the pivoted yoke upon manipulation of the lever varcuately as stated, a tilt rcd passing through the opposed walls of the lift head near the pivoted portions of the yoke, bearings in the yoke arms close to the pivot portions, said bearings slidably receiving the tilt rodrupon movement of the lever` in one direction about the transverse pivot means for the lever, and clamping the tilt rod upon movement of the lever in the opposite direction about said transverse pivot means, means connecting one end of the tilt rod to the tiltable frame whereby the rod in the clamping position of the yoke maintains the frame at various degrees of inclination, and means operative upon rocking the operating shaft for actuating mechanism to operate the lift.

2. In a device of the class described, the combination of a lift to be selectively elevated and lowered, and a weight-supporting frame Vtiltably supported upon the lift, said lift including a head having opposed pivots, a yoke including a pair of spaced arms each mounted upon a pivot of the head whereby the yoke may be rocked about said pivots, an extension on the yoke and a cam follower on the extension, a tilt rod connected to the tiltable frame and supported for sliding reciprocatory'rnovement relative to the lift head, in substantial parallelism with the yoke pivots and closely adjacent thereto, means on the yoke arms for applying a force transversely to the tilt rod in one direction of rocking of the yoke, for clamping the tilt rod in longitudinally adjusted positions, an operating shaft extending from the lift head, and means responsive to rocking of said shaft for actuating mechanism to operate the lift,

a lever for rocking the operating shaft, a cam slidable upon the shaft for movement toward and from the follower of the yoke, for rocking the yoke to clamp and release the lift rod, and means associated with the lever for sliding said cam.

3. In a device of the class described, the combination of a lift to be selectively elevated and lowered, and a weight-supporting frame tiltably supported upon the lift, said lift including a head having opposed pivots, a yoke including a pair of spaced arms each mounted upon a pivot of the head whereby the yoke may be rocked about said pivots, an extension on the yoke and a cam follower on the extension, a tilt rod connected to the tiltable frame and supported for sliding reciprocatory movement relative to the lift head, in substantial parallelism with the yoke pivots and closely adjacent thereto, means on the yoke arms for applying a force transversely to the tilt rod in one direction of rocking of the yoke, for clamping the tilt lrod in longitudinally adjusted positions, an operating shaft extending from the lift head, and means responsive 'torocking of said shaft for actuating mechanism-to-operate the lift, a lever` for rocking the operating shaft, pivot means mountingsaid leverupon the. shaft for movement arcuately in a plane which passes through the shaft axis, a cam slidable upon the shaft for movement toward andfrom the follower ofthe yoke, forv rocking the yoke to alternatively `clamp and release the lift rod, a cam face on the lever and a Vmovable abutment plate on the shaft in position to be advanced by contact with the earn face of the lever when .the latter is moved about its pivot means in the plane which is in the shaft axis, means transmittingy movement of the abutment plate to the cam, and yielding means constantly urging the cam away from the follower of the yoke and for normally maintaining the clamping relationship between the yoke arms Vand the tilt rod.

4. In a device of the class described, the combination of a lift to be selectively elevated and lowered, and a weight-supporting frame tiltably supported upon the lift, said lift including a head having opposed pivots, a yoke including a pair of spaced arms each mounted upon a pivot of the head whereby the yoke may be rocked about said pivots, an extension on the yoke and a cam follower on the extension, a tilt rod coimected to the tiltable frame and supported for sliding reciprocatory movement relative to the lift head, in substantial parallelism with the yoke pivots and closely adjacent thereto, means on the yoke arms for applying a force transversely tothe tilt lrod in one direction of rocking of the yoke, for clamping the tilt rod in longitudinally adjusted positions, an operating yshaft extending from the lift head, and means responsive Vto rocking of said shaft .for actuating mechanism tooperate the lift, a lever for rockingthe operating shaft, a cam slidable upon the shaft for movement toward and from the follower of the yoke, for rocking the yoke to release and clamp the tilt rod, means associated with the lever for sliding said cam in one direction along the shaft, and spring means for constantly urging the cam in the opposite direction along the shaft and for simultaneously maintaining the clamping relationship between the yoke arms andthe tilt rod.

5. In a device of the class described, the'combination of a lift to be selectively elevated and lowered, and a weight-supporting frame tiltably supported upon the lift, an operating shaft and an operating lever rockable in unison with said lever extending beyond the limit of a side of the frame, and including means for actuating mechanism to operate the lift, a connection between the shaft and the lever for pivoting said lever upon the shaft for arcuate swinging movement substantially at right angles to the direction of rocking movement aforesaid, a head on the lift having opposed pivots, a yoke including a pair of arms spaced apart to embrace the exterior of the lift head, said arms being mounted upon said opposed pivots of the head whereby the yoke may be rocked about said pivots, an extension on the yoke and a cam follower on the extension, a tilt rod connected to the tiltable frame and supported for yoke. pivots. and: closely. adjacentY thereto, and meanson. the Yyoke.r arms.: for. applyingy a force transversely to. the. tilt rod in one direction' of rocking of the yoke;` for. clampingthe tilt. rod in longitudinally adjusted positions, anda. cam shiftable. along the operating shaft to a. position of contact with the cam follower ofzthe yoke extension upon swinging of the lever. arcuately Vas stated, the .cam movingthefollower to'irock .the yokeabout its pivots .to releaseandcla'mp the tilt rod.

6. In a .deviceoi thexclass describedr the. combination. of av lift to: be. selectively elevated and lowered, and. a. weight-supporting. frame tiltably supporteduponthe lift,; saidlift including an aperturedhead. wherein the aperturesare opposed and. aligned substantially horizontally, a yoke including .a .pair of spaced integral. arms .extending about and exteriorly of thefhead', and pivot means horizontallynisposed for rockingly supporting the yoke upon the. head, a fixed. extensiony on, the yoke projecting laterally of .the head, a tilt. rod connected to the frame and extended through the aligned head apertures for reciprocatory movement in substantial parallelism with the yoke pivot means andclosely adjacent thereto, .whereby rocking of the yoke brings its .arm into clamping contact vupon the .tilt rod, yielding means acting upon the yoke for normally maintaining the clamping contact aforesaid, an operating lever and a shaft` therefor mounted upon the lift, means pivotally supporting the lever upon theshaft forarcuatezmovement ina plane which. substantially includes the shaft axis, and means operateduponv movement, of the lever'as stated, for engaging the yoke extension and displacing the yoke from clamping .position in opposition to the force oi the yielding. means aforesaid.

.7.In a device of theclassdescribed, the combination of.a `lift including a transversely apertured head to be selectively elevatedand lowered, and a weight-supporting frameincluding a pivot tiltably supporting the frame .upon the lift, means for, actuating the lift including. a shaft rockable in substantial..parallelism. with the supporting pivot of the frame,. and a lever for rocking said shaft, a connectionbetween the shaft and the lever for pivoting saidv lever upon the shaft for arcuateswinging movement substantially at right angles tov the direction of rocking movement aforesaid, means normally -holding the frame against tilting relative^ to the lift, said means including a tilt rod having an endconnected tothe u tilting frame and an opposite end portion received in ltheltransverse aperture of the lift head, an arm pivoted to the lift head for movement in closeV parallelism to the head and transversely againstltheopposite endV portion of the tilt rod, thereby to V`applyfay shearing force to said rod, resilient means for normally yieldingly maintaining the shearing force of the arm against the tilt rod as said rod rests withinwthe aperture of the li-it'head; and a release-means for displacing the arm fromv the shearing position, in opposition to the force ofthe resilient-means operative upon swinging"theleverarcuately at substantially a rig-htangleto the direction of rocking movement ofv the operating shaft. Y

8.In a device of the class described, the combinationloffa `lift including a transversely apertured 'head-to-be selectively elevated and lowered, and-faweiglit-supporting*frame including a pivot ti-ltably supporting the` frame upon the lift, means 'for actuating the lift, including an operating shaft rockable in substantial parallelism with the supporting pivotof the frame and an operating lever forrocking said' shaft, a connection between the'shaft andthe operating lever for pivoting saidfleverfu-ponA theshaft for arcuate swinging movement substantially at rig-ht angles to the directiorrofrofcking' movement aforesaid, a clamping'device' normally clamping the frame against tilting relative to-thelift, saidl device including a tiltv rod having an end connected to the tiltable frame andan opposite'end portionreceivedin-the transversefaperture of the lift head, an arm having' one'of its ends pivoted to the .lift head for movement in close parallelismA with the head t0- ward and from aposition of transverse abutment against saidopposite end portion of the tilt rod, therebyto 'apply a shearing force to said rod, said arm having an vopposite end extending parallel to and cl'oselyladjacent to the rockable operating shaft, resilientA meansn for normally yieldingly maintaining the shearing force of the arm against the tilt rodI as said rodrests within the aperture of .thelift'jheai a camslidable on the operating shaft.y longitudinally, into and out of engagement withsaidfoppositeend of the arm, to move said a'rmfabo'ut its pivot in opposition to the force of the resilient means'upon swinging of the operating lever arcuately atj' substantially a right angl'e'torthe direction ofrocking movement of the'operating shaft; ff

f vii'ialrlnciKoENIGKRAMER.

p 1 .EREDERICK KOENIGKRAMER. 

